HemoCue WBC Manuel D'utilisation page 39

• Pipette or other transfer device (venous samples)
• Lint-free tissue (non-fraying)
Quality Control
The HemoCue WBC Analyzer has an internal qual-
ity control, the "self test". Every time the analyzer is
turned on, it will automatically verify the measurement
performance. When passing the self test, the display
will show the HemoCue symbol and three flashing
dashes, indicating that the analyzer is ready to perform
a measurement. An error code will be displayed if the
self test fails. Another part of the built in self test (QC)
is performed for each measurement, including both
checks of the HemoCue WBC Analyzer but also several
condition checks of the HemoCue WBC Microcuvette and
the sample itself. The operator's ability to handle the
microcuvette and apply the sample correctly is also in-
cluded in these self tests. No additional quality controls
performed by the operator are required for verifica-
tion of the system functionality. Follow local guidelines
regarding quality control procedures. If a quality control
test is to be performed, only use liquid controls recom-
mended by HemoCue, see relevant package insert for
more information.
Expected Values
(Dacie and Lewis Practical Haematology)
Adults 4.0–10.0 x10 /L
9
Children 1 year 6.0–16.0 x10 /L
9
Children 2–6 years 5.0–15.0 x10 9
Children 6–12 years 5.0–13.0 x10
Infants 1 month 5.0–19.0 x10 /L
9
Infants 2 months 5.0–15.0 x10 /L
9
Infants 3–6 months 6.0–18.0 x10
The values above may vary due to a wide range of fac-
tors, such as sex, diurnal variations, exercise, physical
stress or trauma, pregnancy, indigestion of food, and
cigarette smoking.
Measuring Range
Displayed range: 0.3–30.0 x10
300–30000/µL). Results above the measuring range will
be displayed as HHH. Results below the measuring range
will be displayed as LLL.
Limit of Detection
Functional Sensitivity is estimated as the mean concen-
tration for a spiked sample whose CV is 20 %. The Func-
tional Sensitivity has been determined to be 0.3 x10
(James O. Westgaard, Basic Method Validation).
Limit of Blank is defined as the highest measurement
result that indicates that the analyte is not present in
the sample. Limit of Blank has been determined to be
0.06 x10
Limitations of the Method/Procedure
a)
b) Do not remeasure the filled microcuvette.
c)
d) Results above the measuring range will be displayed
e)
/L
9 /L
/L
9
39
/L (300–30000/mm
9
/L (CLSI Document EP17-A).
9
The measurement needs to be started no later than
1 minute after filling the microcuvette.
Mixing samples for an extended period may affect
the result.
as HHH. Results below the measuring range will be
displayed as LLL.
Studies have shown that patient samples with >2 %
nucleated red blood cells (NRBCs) may give falsely
elevated white blood cell count.
,
3
/L
9